Chinese customs officials in Shandong province have seized 60,000 maps intended for export, claiming they “mislabelled Taiwan” and omitted key islands in the South China Sea.

Axar.az, citing BBC, reports that authorities said the maps threatened China’s national unity and territorial integrity because they lacked the nine-dash line—Beijing’s marker for its sweeping maritime claims—and did not show the maritime boundary with Japan.

Beijing insists that Taiwan is part of China, though the island is self-governed and democratic. The seizure comes amid renewed tensions in the South China Sea, following a confrontation between Chinese and Philippine vessels. China frequently confiscates materials it deems politically inaccurate, but the scale of this seizure—60,000 maps—is unusually large.